Beyond the Standard Model with Effective Lagrangians

An Effective Lagrangian description is useful for describing potential physics beyond the Standard Model. The method is illustrated by reference to interactions among the electroweak bosons ($W^\pm$ \& $Z^0$). The resulting estimates of the magnitude of these corrections suggest that they would be at best marginally detectable at high energy $e^-e^+$ colliders or hadron colliders. In loop calculations, contrary to lore, such deviations from Standard Model self-couplings never give observable corrections that grow as a power of the scale $\Lambda$ at which new physics enters, so there are never effects proportional to powers of $\Lambda/M_W$.